flymake-erl

#!/usr/bin/env escript

%% LICENSE: public domain
%% author: karol <dot> skocik <at> gmail

-export([main/1]).

main([Filename]) ->
    {Dir, Options} =
        case emakefile_config(dir_up({filename:split(Filename), []})) of
            false ->
                {filename:dirname(Filename), []};
            {_EmakefileDir, _Options} = Res ->
                Res
        end,
    ok = file:set_cwd(Dir),
    compile:file(Filename, unique(enabled_warnings() ++ Options)).

enabled_warnings() ->
    [warn_obsolete_guard, warn_unused_import, 
     warn_shadow_vars, warn_export_vars,
     strong_validation, report].

unique(Elems) -> gb_sets:to_list(gb_sets:from_list(Elems)).

dir_up({["/"], _}) -> false;
dir_up({Path, RelFilepath}) ->
    {Path1, Prefix} = lists:split(length(Path) - 1, Path),
    {Path1, filename:join(Prefix ++ [RelFilepath])}.

emakefile_config(false) -> false;
emakefile_config({PathElems, RelFilepath} = PW) ->
    Emakefile = filename:join(PathElems ++ ["Emakefile"]),
    case file:consult(Emakefile) of
        {error, enoent} ->
            emakefile_config(dir_up(PW));
        {ok, Forms} ->
            case find_options(Forms, filename:split(RelFilepath)) of
                false ->
                    emakefile_config(dir_up(PW));
                Options ->
                    {filename:dirname(Emakefile), Options}
            end
    end.

find_options([], _) -> false;
find_options([{Filespecs, Options} | T], RelFilepathElems) ->
    F = fun (Spec) -> implies_filepath(Spec, RelFilepathElems) end,
    case lists:any(F, Filespecs) of
        false -> find_options(T, RelFilepathElems);
        true -> Options
    end.

%% TODO: support other than plain '*' patterns
implies_elem({"*", _}) -> true;
implies_elem({X, X}) -> true;
implies_elem(_) -> false.

implies_filepath(Wildcard, FilepathElems) ->
    WildcardElems = filename:split(atom_to_list(Wildcard)),
    case length(WildcardElems) == length(FilepathElems) of
        false ->
            false;
        true ->
            lists:all(fun (X) -> implies_elem(X) end,
                      lists:zip(WildcardElems, FilepathElems))
    end.